The present invention is related to an optical pickup device and an optical disc apparatus.
As background techniques in the related technical field, for instance, JP-A-2004-281026 has been disclosed. That is, JP-A-2004-281026 has described the following problem: While the variation amount of the TE signal amplitudes is defined as ΔPP=(amplitude “a”−amplitude “b”)/(amplitude “a”+amplitude “b”), in such a case that the TE signal is detected by the above-described conventional structure, the variation amount “ΔPP” is 0.69; the offset “oft1” is +33 nm; and the offset “oft2” is −33 nm, namely, which represent the large values. As previously described, if the variation amount “ΔPP” of the TE signal amplitudes is largely varied, then the gain of the tracking control is lowered in the track “Tn−1” and the track “Tn.” As a result, there is such a problem that the tracking control becomes unstable, and thus, information cannot be recorded and reproduced in high reliability. As the solving ways, JP-A-2004-281026 has described the below-mentioned technical idea: A still further optical information apparatus related to the present invention is featured by comprising: an optical source for emerging an optical beam; a light collecting unit for collecting the optical beam emitted from the light source onto an optical storage medium having a track; a branching unit for branching optical beams reflected/diffracted on the optical storage medium; a dividing unit for dividing the branched optical beam based upon a plurality of regions; an optical detecting unit having a plurality of detection regions which detects the optical beams divided by the dividing unit and outputs current signals in response to detected light amounts; a plurality of converting units for converting the current signals outputted from the optical detecting unit into voltage signals; and also, a tracking error signal producing unit for producing a tracking error signal in such a manner that while such a region which mainly contains a tracking error signal component is defined as a first region, and another region which mainly contains an offset component of the tracking error signal among the plurality of regions arranged in the dividing unit, the voltage signal derived from the second region is multiplied by a coefficient, and then, the coefficient-multiplied voltage signal is subtracted from the voltage signal derived from the first region; in which an efficiency under which the optical beams passed through the second region reach the optical detecting unit is high, as compared with another efficiency under which the optical beams passed through the first region reach the optical detecting unit.